Category Archives: Ecology

LGBTSTEMDAY

Today is LGBTQ+ Stem Day. I’m not sure if I am actually someone who works in STEM, because I don’t study and I don’t have anything academic other than a BSc and a Lantra PA1/PA6 (that’s a little joke there for the fellow conservation workers) I saw “STEM supporting” and thought that might be more appropriate for my job?

I might not actually science science, but I do a fair bit of bits of science and I read a lot of sciencey science. I collect data, and write reports, read journal articles, and I assist actual scientists who are working on my reserve.

I also identify as lesbian, although I’m not massively open about it where I live, I don’t think anyone would mind too much. As a LGBTQ+ person, I thought I would write about what I did today, on LGBTSTEM Day.

Last night, myself, two colleagues, a scientist and a friend went to sit in a bog in the middle of the night to listen for nightjars.


We didn’t hear any, but it was still a very pleasant evening. This morning, I drove my colleague, who had stayed at mine after the nightjar expedition, back to her island.

But first we filled up some water butts, because her island doesn’t have any running water, and put them in the truck to drive to the island. Wait! How can you drive to an island? Well, we can because we have a truck, and it’s low tide, and also I have the key to the gate. My colleague protects a breeding colony of Little terns, an incredibly rare seabird in Ireland and the UK. So on the drive we talked a lot about how her colony are doing, issues she’s been having with the public, general chat.

Sea lavender flowering in the salt marsh along the track to the island

On the way back, I stopped off at the Cash & Carry to pick up some household supplies for the reserve, cleaning stuff, bog roll etc.

I had twenty minutes for lunch, then phone and email discussions about whether or not I was going to join some researchers on Saturday, studying a gull colony in the hills about 2 hours drive from here. They wanted to start at 7, so I’d have to leave the house at 5am, mainly so they wouldn’t disturb the birds in the heat of the day, but really so they could get home in time to watch the football. I ended up declining because Saturday is my one day off this week. I’m not going to get up at 430am on my day off, gulls or no gulls.

I then had about 45 minutes to catch up with emails. This includes queries from the public, general work admin, and updating various people about the current state of the bird colony on my reserve. We are coming to the end of the breeding season, and everything should either be fledged or failed, and in my case (as last year) the gull colony is a complete failure.

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A really sad image – many hundreds of dead chicks in a large gull colony

Yesterday we had collected about a dozen dead chicks, and our resident scientist, researching the health and fitness of urban vs rural gulls, and myself drove 2 hours to the government labs to get these autopsied. We had a really good and detailed chat with the Government Veterinary Investigation Officer about what might be causing these die-offs, about other colonies that are also failing, and he brought out stomach contents from a dozen dead chicks we dropped off last week to look at. Is this die-off widespread? Are colonies across the country experiencing the same problems? Is it a Northern Europe issue?

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Equipment round the back of the vet lab

The drive back was even longer due to an accident ahead of us. Once back at the reserve, we went into the colony to check on his study chicks (sadly, all are now deceased or MIA) and change the battery in a gull relay – this is for a separate study, it receives the data from gull GPS tags.

Finally, I had planned on spending a couple of hours rolling bracken, but I was too tired. So I spent half an hour preparing a presentation for a careers talk at the local high school I had been invited to, then myself and our scientist put out a moth trap for the evening. Because moths are cool.

What is happening to the gulls?

It’s World Seabird Day today, so let’s see what is happening at our gull colony.

Back in the late 60s, the colony of Lesser black-backed and herring gulls at South Walney was the biggest in Europe, with about 45,000 pairs of these gorgeous characterful birds nesting. When my colleague and I completed this year’s transect back at the end of May, there were just over 3,500 pairs. This is a huge decline, but actually a slight improvement on last year, however that could just be stats as we count quadrats and multiply up, and I had readjusted some of the quadrat locations.

Still, we would like to not get any smaller, and I hope through predator deterrence we could increase and be stable at about 5,000 pairs, possibly recruiting urban gulls driven out from nearby towns.

Ideally, gulls lay 3 eggs, and most can usually get at least one fledged, if all goes well; sometimes if all goes very well they get two away, I don’t think they ever manage to raise all three. When the colony was at its height, it was estimated to have a productivity rate of 0.7 chicks fledged for each pair. When predation became a problem (I am told foxes only arrived on Walney in the 1990s) this fell to about 0.2 or 0.3 chicks fledged per pair.

We have electric fences, which now are mains powered and can be maintained at over 7,000 volts – a nasty shock to deter even hungry foxes. The colony was also incredibly dense, with nests at the centre only a foot away from each other, and this density of gulls in a colony can easily drive away aerial predators, such as magpies or kestrels.

So we were confident that we might have an exceptionally good year – except by mid June, it was clear that something had gone horribly wrong. Instead of thousands of fluffy gull chicks, there just didn’t seem to be any at all. As the end of June was reached, the BTO and Natural England arrived hoping to ring several hundred chicks; they found only 9 big enough to ring. It was devastating but seemed that the colony had failed.

We found 9 fresh dead chicks and one dead adult, and took them to the Animal & Plant Health Agency’s lab for a post-mortem. I had seen a colony collapse like this before, working a few years ago at a gull colony in the north of Cumbria, also managed by Cumbria Wildlife Trust, which has failed for nearly ten years running. Post-mortem there revealed that the chicks were being pecked to death by adults, who were presumably stressed, although it’s difficult to say why. The gulls nesting on a nearby industrial estate had no problem fledging young.

At that site, it was difficult getting any further. Here at South Walney, however, we are very lucky that we have hosted gull research for decades, and despite the dwindling numbers, it’s still a nationally important site for these birds.

The post-mortem of the gull chicks showed that all 9 had starved; their stomachs were empty. Conversely, the adult bird was in good condition and had actually eaten itself to death gorging on earthworms. I emailed these results to the BTO researchers working at South Walney this year, and also to our regional Natural England contact, expecting just commiseration. Instead, a proper investigation into what has happened is being driven forward – why have none of the gulls gotten enough food? Has a food source collapsed somewhere?

This really highlights how our noisy neighbours can act as an “early warning” for a marine ecosystem that’s so often out of sight. Has a mussel bank disappeared? Has a fish population crashed? This morning myself and two colleagues went back to the colony, to count chicks and collect food pellets.

After a walk through of the whole colony, we counted just 53 chicks, all about the same age – 3ish weeks – and no fresh corpses, which suggests that all the other chicks died at roughly the same time, but that the chicks alive now should hopefully make it as the parent birds were clearly finding food somewhere.

Like owls and other birds of prey, gulls eat food whole and then regurgitate anything they can’t digest in a tightly packed pellet. We collected 38 pellets this morning, and dissected them to see what the gulls had been eating.

This isn’t a robust method, because the gulls will eat lots of soft things that won’t be represented in a pellet. But it gives us some idea. By far, the majority of pellets contained a fair bit of vegetable matter, and plastic, sadly typical. There was a low percentage of mussels, but that’s because mussel shells don’t form into pellets (they just sort of scatter everywhere) so I hadn’t collected many. We found the remains of a small rodent, and beetles, but what we didn’t find were very many fish bones or scales.

Next, I want to go back and collect more pellets, and make more note of how many piles of mussel shells there are. Because the BTO have been tagging birds at South Walney with GPS trackers, we know where they are going to feed – the next step would be physically going there ourselves and see what is going on.

Next Holiday Sorted

A piece about owls in the Guardian mentions Kikinda in northern Serbia:

“.. up to 750 long-eared owls – part of this species’ largest concentration on the planet – roost every night in the town’s main streets …

“At dawn the entire town is caught in sunlit hoar frost, and as the residents stroll to work or their lessons, they thread through the parallel world of these night birds. The owls are utterly indifferent, their eyelids squeezed tight like closed shutters, holding aloof from the human community and stopping up in the darkness of their dreams all that gloriously unknowable magic of their lives.”

Booking holiday now.

Shed Hibernator

Here on the reserve we have several old World War II buildings, in various states of decay, some so perilously close to collapse we are absolutely not to go into them under any circumstances.

So I was having a nose through that one, a concrete shell we used to use as a fencing post storage but during the war was a massive searchlight post. Moving aside some mouldy cardboard I spotted several spiders and insects hibernating, including some lepidoptera! hooray!

This Herald moth is absolutely stunning! I don’t think I’ve seen one before.

Nearby were these two small tortoishell (cheers Sean for IDing, go #teammoth):

I look forward to seeing them in the Spring!

I was in the vicinity as I searched for a badger sett in the dunes. I had heard rumour there was one, and seen tracks here, so I spent a good twenty minutes following reasonably fresh badger tracks – always a fun thing to do! Badger prints are broad, with the toes in a row, and with clear claw marks:

There’s plenty of rabbit holes and digging in the dunes, but the entrance to a badger sett is a more sideways “D” shaped – rabbit burrows are taller than they are wide. And badgers tend to keep their sett entrances clean and tidy, while rabbits like a big mess.

Another nice sign of an active badger sett, rather than a big rabbit hole, is nice clear badger footprints leading straight out of it! (on the right of the picture)

Gannets

Incredible pictures in the Daily Mail of gannets on Grassholm (off South West Wales) tangled in the fishing and plastic discard that’s become a carpet as birds use it to build their nests. The photos are by Sam Hobson.

Gannets are stunning, large sea birds, perfectly streamlined, they fish by diving at 60mph into the sea. They nest in just a handful of packed colonies (gannetries), most of which are around the British Isles, the largest being on Saint Kilda (59,622 birds), Bass Rock in the Firth of Forth (49,098) and Grassholm, off the coast of Wales (32,094). (These are the most recent survey numbers, which I got from the JNCC’s website. Very interesting to see that there are some birds known to nest on Rockall.)

The RSPB, who manage Grassholm, send a team out every year at the end of the breeding season to free birds that have become entangled. The sight of the plastic really brings home the scale of plastic pollution in the oceans.

I visited Grassholm in 2006, the first time I’d visited a gannetry. The spectacle of thousands of these stunning birds was unforgettable, as was the sight of so much brightly-coloured plastic in amongst the nests that covered the rock.

Grassholm in 2006

The next Gannetry I visited was that on Saint Kilda, this summer. And we had another run in with gannets and plastics – while we were conducting an offshore count of cliff-nesting birds, our expert crew, Angus and young David, spotted something in the water.

They began calling to each other in Gaelic as Angus carefully maneuvered the boat and young David got a grappling hook. After a few attempts, he managed to pull in two gannets who were tangled up together, their bills completely wrapped up in nylon filament from fishing discard.

Beautiful eyes!
Beautiful gannet

My colleagues carefully cut the birds free, and after a pose for photos, they went on their way.

While on boat survey, the boatmen, Angus and David of <a href="http://http://www.kildacruises.co.uk">Kilda Cruises</a>, spotted 2 gannets struggling in the water. Hauling them on board, their bills were tangled up together in nylon filament. Using filleting knives and nail scissors, my colleagues and the boatmen managed to free them. So wonderful to save them, and a treat to see gannets at close hand like this!

Angus told David that's the only bird he was picking up this weekend.
“that’ll be the only bird you pick up this weekend, David”

Undoubtedly, without quick eye and action of our boatmen, they would have drowned or starved miserably.

MouseCam: The sniffening

I had a quick look at the cam that’s looking at the mousecam. I put this one so I can check it from a distance to see if anything has been near the Bucket Trap that houses Mousecam, without leaving human-scent all over the BucketTrap

GUESS WHAT

ha! Typical!

So a dark tabby cat comes at about 7pm last night and finds two things behind the camera trap, and quickly carries them off. I’m sure there was nothing there when I put the trap out, and they don’t look like rodents:



What on earth..? I baited the trap by putting lumps of peanut butter on the inside, but the cat appears to have found something solid. How utterly weird! The cat then sniffs about, presumably licking off the peanut butter from where I had put some around the trap’s entrances

It comes back again at half nine, and again at around midnight – and there’s nothing else on the camera! I think this is probably a feral or farm cat. Cheeky thing, guess I needn’t have worried about leaving human-scent all over the bucket!

MouseCam

I was wondering about how to do a small mammal survey on the reserve, the last having been carried out in 1994. I want to get a good idea of what species we have, and the usual way to do this would be with small live traps called Longworth Traps, which are tried and tested and have been used in small mammal survey for nearly 70 years!

These traps are expensive and time-consuming, as they need to be checked ever 12 hours (or less), and once it’s been triggered it won’t register anything else until you’ve been along to have a look, released the catch and reset it.

So I thought about how I could use one of our Trailcams, a motion-activated camera with an infra-red flash and lens (for taking pictures at night) and found a paper called A novel method for camera-trapping small mammals. In it, they use a large plastic barrel with the base cut out, and a camera pointing down into it. The base is replaced with a gridded floor, and baited, so that small mammals entering are seen from above and measurements for size can be seen:

Figure 1: Floating camera trap for small mammals, tested in Florida, USA, during February 2012 to February 2013. The 7-gallon (26.5-L) bucket sits on a base that floats when the tide is high and fiberglass poles keep the trap in place. Lid will be painted white for heat deflection.

Figure 3: Species captured in camera trap to demonstrate ease of identification. Species include (clockwise from top left; a) Microtus pennsylvanicus dukecampbelli and Sigmodon hispidus, b) Oryzomys palustris and S. hispidus, c) M. pennsylvanicus dukecampbelli and O. palustris, and d) O. palustris, M. pennsylvanicus dukecampbelli, and S. hispidus. Trap was tested in Florida, USA, during February 2012 to February 2013.

Additionally, as they want to use it in a tidal area, they affix it to a large float, and then so long as it is baited, it can be left alone.

I thought that sounds like it might be quite interesting! First I’ll need a large plastic bucket with the base cut out… Luckily, the sea provides us with plenty of rubbish, including a large plastic bucket with the base cut out. How convenient.

I fixed some L-shaped brackets, to hold an off-cut of corrugated plastic sheeting in place, then cut a hole in that for the camera to sit, so the whole thing looks like this:

Not very hi-tec! I drilled a few small entrance holes, put it out in the yard and baited it, along with the second camera trap pointed at it to see if anything shows interest but doesn’t go inside.

I’ll have a check of it after a few days. I’ve just put it in the yard here rather than out on the reserve already because I believe as it is, it won’t focus on something as near, and the infra-red flash will be far too bright! They’re designed to take pictures up to about 14m away. But it would be good to get a feel for how it works to start off with.

White Curlew

I’ve started wardening a Nature Reserve on the Cumbrian Coast, which is very exciting. Until moth season starts up again I’ll just have to bore you with pictures of scenery and birds and stuff.

There’s plenty of wintering birds here, oystercatcher, redshank, curlew, dunlin, sanderling, turnstone and grey plover, mostly. I had heard rumour of a leucistic curlew that had been seen for a few years now. Leucistic is when the bird doesn’t have a dark pigmentation, not albino as there might still be some colour, but pale. I found an actual photograph of one in a drawer (along with thousands of other, undated, unlabeled photographs), so set out on a mission to find what I decided was now called Luke. Moby Luke, because it was white, I kept searching for it and wasn’t sure it even existed.

I spotted it a few times, way out on the flats, hanging with some little egrets. After a few weeks, this was the best picture I’d managed of it:


Amazing.

On Friday evening, I set off to work’s Christmas Lunch as the tide was coming in and – wow! there was Moby Luke right by the track. I did a 5-point turn and sped back to get my camera, resulting in these great pictures:

 

Next week I’ll compare it to the old photo and see if it’s the same bird.

Also: how great are Curlew bills?

Moths &c

It was a muggy, warm night last night and this morning, so I was hoping to get something other than November moths in the 150w Robinson trap I put out before bed last night.

Well I did!

Two lovely Feathered thorn, Colotois pennaria, in the trap this morning, alongside a dozen or so November Moths (another aggregate species, could be one of four species but IDing is difficult without dissection!), this red-green carpet:

and… two of these wonderful Hawthorn shieldbugs, Acanthosoma haemorrhoidale:

an Orange ladybird:

Orange ladybirds were, until 1987, used as indicator species of ancient woodland. Then the ladybirds discovered sycamore, and more recently Ash, trees, and their numbers are increasing.